Magnetic separator



Dec. 2, 1969 H. SPODIG 3,481,471

MAGNETIC SEPARATOR Filed July 25, 1968 IYNVENIOR "Ell/RICH 5900/;

WWW/0e! IJ Z-Mr MW???) United States Patent Int. 01. misc 1/12 U.S. Cl. 210222 5 Claims ABSTRACT OF THE DISCLOSURE A magnetic separator for separating magnetizable and non-magnetizable contaminants from a liquid includes a housing of magnetizable material. A magnetic roller is mounted for rotation in the housing so as to define therewith a restricted gap through which the liquid flows. The magnetizable contaminants are attracted to the roller while the latter is stationary and accumulate so as to extend across the gap in form of projections through which the liquid must pass. The projections thus act as mechanical filters for the non-magnetizable contaminants and at the same time restrict the flow of liquid so that the liquid level will rise upstream of the accumulated projections. A float is arranged upstream of the projections and connected with the drive for the roller so as to energize the drive when the liquid reaches a predetermined level. The rotation of the roller results in removal of the projections and of the non-magnetizable contaminants entrapped therein from the gap.

BACKGROUND OF THE INVENTION The present invention relates generally to magnetic separators, and more particularly to a magnetic separator for separating magnetizable and non-magnetizable contaminants from a liquid.

It is already known to utilize magnetic separators for separating magnetizable particles, hereafter identified as contaminants, from a liquid. This is done, for instance, where metallic particles are to be removed from the lubricating oil of an engine although there are of course many other applications of this principle. These separators usually comprise a housing and a magnetic roller mounted for rotation within the housing and defining with the latter a gap through which the contaminated liquid flows. The magnetizable contaminants are attracted to the roller and the latter is rotated so as to remove them from the gap and thereby separate them from the liquid. The separation of the magnetizable contaminants from the magnetic roller is effected by a so-called wiper which is arranged so as to wipe the contaminants adhering to the surface of the roller 0E this surface during rotation of the roller.

Such constructions are highly efficient in separating magnetizable contaminants from liquids. They do not, however, constitute a significant aid in separating from the same liquid such other contaminants of a non-magnetizable nature as are frequently also present in the liquid.

It is therefore a general object of the present invention to provide a magnetic separator which is capable not only of separating magnetizable particles for contaminants from a liquid, but also of removing from the same liquid non-magnetizable contaminants present therein.

SUMMARY OF THE INVENTION In accordance with one feature of my invention I provide, in a magnetic separator of the type here under discussion, a housing consisting of magnetizable material. A normally stationary magnetic roller is mounted in the housing for rotation about a predetermined axis and defines with the housing a restricted gap extending longitudinally of the roller. A magnetic field extends across this gap between the roller and the housing. An inlet and an outlet are respectively provided in the housing and communicate with the gap adjacent the opposite ends of the roller so that a stream of liquid containing magnetizable and non-magnetizable contaminants may flow through the gap from the inlet to the outlet. During such flow the magnetizable contaminants are attracted to the roller, forming thereon during continued accumulation one or more projections, the so-called beards, which extend across the gap toward the housing wall. Eventually, such projection or projections will extend completely across the gap so that liquid which continues to flow through the gap must filter through the projection or projections. Evidently, magnetizable contaminants contained in such liquid will add to the size of the projection, being attracted thereto, and non-magnetizable contaminants will be entrapped in the interstices existing between the individual particles which in toto constitute the projection. Thus, the projection or projections consisting of the separated magnetizable contaminants will serve as a mechanical filter for non-magnetizable contaminants.

In accordance with the invention I provide drive means which is operatively associated with the roller and which is adapted to rotate the same, and sensing means which is associated with the drive means and which is positioned and arranged upstream of the projection extending across the gap. Evidently, the projection or projections will act in the manner of a filter cake in that they will serve to restrict the flow of liquid through the gap, causing the liquid level upstream of the projection or projections to rise. The sensing means is constructed and arranged so as to energize the drive, and effect in this manner rotation of the roller, when the liquid upstream of the projection or projections reaches a predetermined level. The roller then rotates in conventional manner and the magnetizable and non-magnetizable cotaminants thereon are removed in the manner known from the art. This result-s in a decrease in the level of the liquid in the gap and in the energization of the drive through the intermediary of the sensing means whereupon the process of accumulation and filtering begins again.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THE DRAWING The single figure is a vertical longitudinal section through an apparatus embodying the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the drawing a housing 1 consists of ferromagnetic material. A magnetic roller is identified with reference numeral 2. The roller 2 in the illustrated embodiment is of multi-pole construction and consists of several axially arrayed permanent magnetic sections. In this embodiment the outer peripheral surface of the roller 2 is stepped in accordance with the juncture between the individual sections. It is to be understood, however, that the outer surface could also be smooth. The features thus far dis cussed are already known in the art.

The housing 1 is provided adjacent one axial end of the roller 2 with an inlet 5 which communicates with the liquid supply conduit 4 on the one hand, and with the restricted flow-through gap 7 defined between the inner surface of th housing 1 and the outer peripheral surface of the roller 2. Arranged adjacent the other end of the roller 2, and also communicating with the gap 7, is an outlet 6 for processed liquid.

It will be appreciated that in the illustrated embodiment magnetic fields extend across the gap 7 between the sec tions of the roller 2 and the housing 1. As liquid containing magnetizable and non-magnetizable contaminants flows through the gap 7 from the inlet 5 to the outlet 6 of the housing 1, the roller 2 will normally be stationary. Under the influenc of the magnetic fields the magnetizable contaminants contained in the liquid will be attracted to the peripheral surface of the roller 2 and will accumulate thereon in form of projections or beards which extend into the gap 7 and which will extend eventually all the way across the gap closing the same. When this takes place, that is when these projections contact the inner surface of the housing 1, they will act as filters in which the non-magnetizable contaminants contained in the liquid flowing through the gap 7 from the inlet 5 through the outlet 6 become entrapped. Of course, the presence of these projections which are being constantly increased in density by newly-attracted magnetizable contaminants as well as by the non-magnetizable contaminants being trapped, restricts the passage of liquid through the gap 7 and will cause the level of liquid upstream of the projections to rise.

In accordance with the present invention I provide sensing means 3, which in the illustrated embodiment is assumed to be a float responsive to fluctuations in the liquid level, and the sensing means 3 is operatively associated with the drive 8, which may be an electro motor, for the roller 2. The drive 8 is adapted to rotate the roller 2 about is predetermined axis of rotation determined by the shaft of the roller which is journalled in the illustrated bearings. The sensing means is so arranged that it will energize the drive means 8, causing the latter to rotate the roller 2, when the level of liquid upstream of the projections consisting of magnetizable and non-magnetizable contaminants reaches a predetermned point. In the illustrated embodiment which represents the construction I currently prefer, the sensing means or float 3 is located on the level of the axis of rotation of the roller 2. It Will be appreciated that, when the liquid reaches this level, the float energizes the drive means 8 and the latter causes the roller 2 to rotate about its axis of rotation. Details concerning the specific construction of the float and of the connection between the same and the drive means 8 are not believed to be necessary; any sensing means capable of responding to a rise in the level of the liquid to a predetermined point and of generating a signal for energization of the drive means 8 is suitable for the purposes of the invention. Similarly, operative connection between such sensing means and the drive means is Well know to those skilled in this field.

Rotation of the roller 2 lifts the accumulated projections consisting of magnetizable and non-magnetizable contaminants out of the gap 7 so that they can be removed from the roller 2 in the usual manner, for instance by engagement with a wiping means. Of course, as the obstruction or obstructions in the gap 7 are thus removed, the level of liquid will be rigidly dropped, the generation of the drive-means energizing signal by the sensing means 3 will cease, and the drive means 8 will be arrested so that the roller stops its rotation. Now the previous process repeats itself.

By resorting to my invention it is thus possible not only to remove magnetizable contaminants from a liquid in the highly eflicient manner which is already known from magnetic separators, but also to utilize such a magnetic separator for simultaneously removing non-magnetizable contaminants from the liquid. This eliminates the need for a separate filtering step, speeding the processing and purification of the liquid and making it possible to save the expenses otherwise necessary for providing a filtering device capable of removing the nonmagnetizable contaminants.

As pointed out earlier, the peripheral surface of the roller 2 may be smooth rather than profiled or stepped, that is the roller need not consist of a plurality of individual sections, and the roller may also be directly magnetically connected with the magnetizable housing in which case the latter in effect constitutes an auxiliary pole for the magnet roller which under these circumstances is unipolar.

It will be undestood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions dilfering from the types described above.

While the invention has been illustrated and described as embodied in a magnetic separator, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analyses, the foregoing will so fully reveal the gist of the present invention that others can by applying current knowledge readily adapt it for various applications Without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.

What is claimed as new and desired to be protected by Letters Patent is set forth in the appended claims.

I claim:

1. In a magnetic separator, in combination, a housing of magnetizable material; a normally stationary magnetic roller mounted in said housing for rotation about a predetermined axis and defining with said housing a restricted gap extending longitudinally of the roller, a magnetic field extending across said gap between said roller and said housing; inlet means and outlet means provided in said housing and communicating with said gap adjacent the opposite ends of said roller so that a stream of liquid containing magnetizable and non-magnetizable contaminants may flow from said inlet means to said outlet means whereby the magnetizable contaminants are attracted to said roller and accumulate thereon in form of projections which extend across said gap and constitute filters for the non magnetizable contaminants and flow-restrictors for the liquid which consequently rises upstream of such projections; drive means associated with said roller and adapted to rotate the same; and sensing means asociated with said drive means positioned and operative for starting and stopping operation of said drive means in response to the liquid upstream of the projections respectively rising to and descending below a predetermined level.

2. In a magnetic separator as defined in claim 1, wherein said sensing means is arranged for starting and stopping operation of said drive means in response to the liquid rising to and descending below the level of said axis of rotation.

3. In a magnetic separator as defined in claim 1, said roller having a profiled outer peripheral surface.

4. In a magnetic separator as defined in claim 1, said roller comprising a plurality of axially arrayed sections, a separate magnetic field extending across said gap between said housing and each of said sections.

5. In a magnetic separator as defined in claim 1, wherein the interior of said housing is of substantially U-shaped cross-section and said gap is of arcuately curved cross-sectional configuration.

References Cited UNITED STATES PATENTS 2,678,729 5/1954 Spodig 210222 REUBEN FRIEDMAN, Primary Examiner T. A. GRANGER, Assistant Examiner 

